how to make a stroke, like in vector software (illustrator, flash, animate, etc.), with a round cap?
a solution (that is not perfect):
Make a square plane and a filled circle of the same size (it's important that their origin is in their middle)
Create a Bézier curve which has the same origin as the square.
On the plane, add an Array modifier&gt;Fit type&gt;Fit Curve as well as a Curve modifier.
This creates a curve that follows exactly the Bézier curve. (see picture for details)
Then with the Array modifier, it is possible to add Start/End Caps. Selected the circle if you want Round Caps. With a few adjustments and a Subdivision modifier it works.
To secure the whole thing, I advise adding 2 Object Constraints on the Bézier curve: CopyTransform (the plane) and Limit Distance (0 m) (see picture for details).
This blocks most of the possible problems that you will get if you try to move the plane object.
This method doesn't let you easily change the width of the stroke (which depends on the plane's size)
Trying to scale the whole thing might get you in trouble and break the link between the plane and the Bézier Curve.
Good Luck!!